What if it’s as bad as you think? What if behind the picket fence and brocade curtains, your neighbors really are holding hands by the fire? They’re calling each other “sweetheart” and talking about their feelings before heading to the bedroom for another round of magic-making. What if that’s what everyone’s doing? Everyone except you.

You, meanwhile, are silently fuming as you fold your fifth load of laundry, still sour from this morning’s fight about who was supposed to pack the kids’ lunches and whose idea it was to have this many kids in the first place. And what you want, with every yearning, lust-filled fiber of your being, is to go to sleep.

The latest attempt to find out what’s going on in everybody else’s relationships is “The Normal Bar,” a book based on surveys of more than 70,000 people about their marital satisfaction.

The results show that most people (74 percent) are happy in their relationship. Only 15 percent say they’ve had an affair, though the numbers rise when the question is phrased in terms of “sex outside your current relationship.” Then 33 percent of men and 19 percent of women admitted cheating.

But before we dive under the covers, we should say, as co-authors Chrisanna Northrup, Pepper Schwartz and James Witte note, that this is not an academic study based on a random, representative sample of the population. The information was gathered via Web surveys promoted on Huffington Post, Reader’s Digest, AOL and AARP. As Witte, who heads George Mason University’s Center for Social Science Research, put it, the survey results reflect the views of “the people likely to buy the book.” (That is, educated, media-savvy, middle-aged folk who are mostly women.)

HANDOUT IMAGE: Authors of "The Normal Bar." From left: Pepper Schwartz, Chrisanna Northrup and James Witte. (Credit: Megan Baker Photography) (For reprints contact: Ellen Folan, efolan@randomhouse.com) ONE TIME USE, NO SALES (MEGAN BAKER PHOTOGRAPHY/MEGAN BAKER PHOTOGRAPHY)

So, what were these anonymous survey-takers willing to disclose about their most intimate relationships? To start, 66 percent of them believe their partner is their soulmate. And while only 28 percent of women said they fell in love at first sight, 48 percent of men said they did. In the end it didn’t much matter, because couples who fell in love slowly were just as happy as those who were thunderstruck.

As to the question of whether to marry your opposite or someone just like you, among those couples who are very similar, 95 percent are “extremely happy,” which should make that eHarmony guy smile as he counts his vacation homes.

The authors found that certain behaviors correlated with high satisfaction among couples: Happy couples often go on date nights, call each other pet names, hold hands, kiss passionately, give each other back rubs and say “I love you.”

“It was very eye opening how simple, tiny things can make a huge impact,” says Northrup, who conceived of “The Normal Bar” after a crisis in her own relationship. Four years ago, Northrup, a 41-year-old San Diego mother of three, moved out because her marriage of 15 years wasn’t what she hoped it would be.

“I pictured more passion, more fun, more love,” she says.

Northrup and her husband spent two years in couples therapy, but what she really wanted to know was how the “normal” in their relationship stacked up against other people’s. “What are my peers doing and more importantly what are my happier peers doing and what can I learn from them?” she wondered.

Northrup got in touch with Witte and Schwartz, a Seattle sociologist who studies relationships, and drafted the 1,300-question survey.

HANDOUT IMAGE: "The Normal Bar" by Chrisanna Northrup, Pepper Schwartz and James Witte. (Credit: Harmony Books) (Downloaded with permission from http://smartpublic.randomhouse.com) (Harmony Books/HARMONY BOOKS)

The team found that both sexes said communication was the thing they valued most — and people in unhappy relationships said it was the No. 1 thing they were lacking.

At the same time, 33 percent of American women and 43 percent of men admitted keeping secrets from their mate. Forty percent of respondents reported being unhappy with their partner’s weight, and nearly a third of people felt their partner put their job ahead of the relationship. (All that work might not be worth it: Folks who earned $250,000 to $500,000 fought more about money than people earning less than $20,000.)

As for action in the bedroom, 40 percent of people said they have sex three or four times a week, and 27 percent have sex “a handful of times” each month. A very busy 7.5 percent of respondents have sex daily, while 17.5 percent said they have sex rarely or never.

But isn’t the idea of what’s “normal” a little problematic?

“This isn’t about being average or part of the flock,” Schwartz says. Instead, she says, it’s about adopting techniques that might make a good relationship better. “I really want people to treat their marriage like a living, breathing organism. If you don’t give it the things it needs, it’s going to shrivel or limp along.”

For the record, Northrup and her husband stayed together. And she says that since the surveys rolled in and they started talking about the results and implementing some of the behaviors, they’ve become happier than ever.

She now calls her husband “sweetheart.”